I'm currently working on a AGV with Arduino Duemilanove + CMUcam 2 and am having some hard time trying to read serial data sent by the CMUcam. I succesfully managed to send serial data from the Arduino to the CMU-CAM, but reading is really hard. The camera sends back a data packet of this type: "T mx my x1 y1 x2 y2 pixels confidence\r", where "mx, my" and the rest are some numbers with informations I need to process.

The problem is: how do I isolate what I need in that packet and store them into variables? In my case, I need to get only the "mx" and "my" values, but the serial sends everything altogether.

In my case, I need to get only the "mx" and "my" values, but the serial sends everything altogether.

The "serial" doesn't send anything. The camera does. It sends a stream of characters that presumably mean something to the receiver.

How are you reading/capturing that data now? The answer to that has a lot to do with how you then parse the data. If you are doing it right, storing the data in a char array, the strtok() and atoi() or atof() functions might be worth looking into.

Right now I'm just storing the whole packet in a variable, but what I need is to 'filter' the packet and store only what I need, that is, the 'mx' and 'my' values. How can I get only these values and store 'em into separate buffers?

Right now I'm just storing the whole packet in a variable, but what I need is to 'filter' the packet and store only what I need, that is, the 'mx' and 'my' values. How can I get only these values and store 'em into separate buffers?

That depends on the type of the variable that you are currently storing the data in.

Just curious how do you want to store a RGB like image of a cam on a arduino, or what would you like to do with the received data.Because I mean even a small cam lets say (800 x 600 pixels x 3 colors) requires 1.44 Mb thats more then a arduino has.

( i'm curious since i had been thinking of using cams with arduino to, and then abandoned the idea in favor of a cheap ITX motherboard )

while (Serial.available()) { // get the new byte: char inChar = (char)Serial.read(); // add it to the inputString: inputString += inChar; // if the incoming character is a newline, set a flag // so the main loop can do something about it: if (inChar == '\n') { stringComplete = true; } }

So, look at the String class. Look at methods for finding characters, like the comma that separates values. Look at methods for extracting parts of the String as a substring. Look for methods for converting a (sub)String to an int.

The needed methods all exist. You just need to call them in the right order.

Or, better, ditch the String class, use a char array and strtok() and atoi().

Now, another doubt.. on the CMUcam manual, it's said that the packet sent back comes in ASCII viewable format. On the LCD, for example, it comes as something like "T 23 12 52 42 ..". But, how does it arrives to the Arduino? Is it in Decimal, Hex? I can't monitor it on the Serial Monitor, because Duemilanove has only one Serial Port.

If I use the SoftwareSerial, than the RxTx for USB comm is going to be available? Because when I plugged the RxTx pins for the camera, I could not connect the Arduino to my PC. Guess I'll have to try it out.

With the LCD I can see that it comes as 'the real values', but I fear that the Arduino may read it as Decimal or even Hex, not the real thing.